Which tests are considered key laboratory evaluations for kidney function?

The key laboratory evaluations for kidney function are serum creatinine and blood urea nitrogen (BUN) because both of these tests provide crucial information about how well the kidneys are functioning.

Serum creatinine is a waste product that is produced from muscle metabolism and is normally excreted by the kidneys. Elevated levels can indicate impaired kidney function since it suggests that the kidneys are not filtering creatinine out of the blood effectively. Blood urea nitrogen (BUN) measures the amount of urea nitrogen in the blood, which is also a waste product filtered by the kidneys. High levels of BUN can also signal kidney dysfunction, along with conditions such as dehydration or excessive protein intake.

Together, these tests help clinicians evaluate glomerular filtration rate (GFR) indirectly, which is essential for assessing overall kidney health. In contrast, the other options do not directly evaluate kidney function. Complete blood count and liver function tests focus on hematological and liver health, arterial blood gases and lactate levels are primarily used to assess respiratory function and metabolic status, and imaging studies like X-rays and MRI scans do not provide biochemical insight into kidney function.